Figure 1. The Bešeňová elevation – structural and temperature profile.

Application and interpretation of silica-

geothermometry in low enthalpy geothermal systems. Case study on the Bešeňová elevation hydrogeothermal structure, northern Slovakia.

Branislav Fričovský, Ladislav Tometz

Institute of Geosciences, Faculty BERG

Technical University of Košice

040 01 Košice, Slovak Republic

branislav.fricovsky@tuke.sk, ladislav.tometz@tuke.sk

Veronika Blanárová, Marián Fendek

Dept. of Engineering Geology and Hydrogeology

Faculty of Natural Sciences, Comenius University

Bratislava, Slovak Republic

fendek@fns.uniba.sk, blanarova@fns.uniba.sk

Abstract— Silica geothermometers for boiling and no steam loss

case are examined test accuracy on basal temperatures

estimation for each of selected zone and to contribute on overall

geochemical conceptual model (mixing, boiling, equilibrium

attainment). Use of chalcedony geothermometers appears

suitable only, moreover, merely for a case of deep reservoir, with

mean temperature calculated of 75°C.

Keywords- equilibrium; geothermometry; mixing; silica

I. INTRODUCTION

Different chemistry of geofluids reflects various magnitudes of mineral-solute or solute-solute reactions and environment they associate with. Geothermometers, empirical equilibrium functions between water and solutes implying provenance zone temperature take advantage in slowness of initial conditions re-equilibration at cooler temperatures. While conformity between individual geothermometers validates calculated results, discrepancies are indicative of dis-equilibrium, providing outcomes for interpretation and quantification of various processes such as mixing, boiling or rock dissolution. Silica geothermometry regards to solubility of all silica species at particular temperature and pressure conditions, controlling SiO2 concentration in thermal fluids.

II. THE BEŠEŇOVÁ ELEVATION

A. Geological structure

The Bešeňová elevation represents low enthalpy stratified hydrogeothermal system within western part of the Liptov Basin, where two reservoir zones are distinguished [1] (Fig. 1). The shallow reservoir associates with Eocene conglomerates, breccias and detritic carbonates of the Inner Western Carpathian Paleogene (IWCP) hydraulically connected to Mid Triassic dolomites of the Choč Nappe. The bottom reservoir is recognized within Mid Triassic carbonates. In between, Late Triassic aquiclude of siliciclastics rich in sulphates and Jurassic – Mid Cretaceous aquitard of organogene and pelitic carbonates with high K-, Mg-, and Na- minerals content separate both aquifers [2]. While shallow zone is insulated at a top by Oligocene claystones, flysch and minor sandstones typical in high silicates content, a deep reservoir impermeable bedrock represent Early Triassic siliciclastics typical in increased sulphates content [3, 4].

B. Review on conceptual model

The system is recognized hydrogeologically open [2],

including recharge zone of Kľačianka valley (SE) [5, 6], central accumulation zone [2] and discharge zone close to Vyšné Sliače (SW). Lateral westwards fluids transition from neighboring Liptovská Mara depression contributes only on minor [2, 7]. Arrangement complexity defines contacts (TTM – thermal-thermal; TCM – thermal-cold) between hydrofacies of various provenances and chemistry (Fig. 2). Infiltration progrades in separate channels (top – cold and fast; bottom – tempered and slow), connected prior to conjoint transition into shallow and deep aquifers. A process is controlled by stability of carbonates and clay minerals [7]. Geofluids of deep reservoir suffer only minor hydrogeochemistry degradation by intakes from deep transition, where dissolution of carbonates and sulphates [7, 8] prevails. Mixing realizes within shallow zone, as autochthonous waters are invaded by tectonics connected ascend of facies from deep reservoir (TTM) at a base, prior to mixing with entering infiltrations from shallow transition (TCM), giving an origin to secondary fluids. Diversion takes place after, as part of waters ascends along open faults up to a surface manifested as springs and travertine

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domes nearby Bešeňová after loss in CO2 [6, 7]. Fluids not involved in upwelling accommodate within zone and contribute on various rock dissolution and precipitation processes. At the discharge zone, tempered infiltrations of short residency disintegrating carbonates come into TCM contact with laterally leaking thermal fluids from deep reservoir depositing carbonates prior they mix and dispose as springs. Only questionable evidence of boiling is implied by enthalpy-chloride model [8].

C. Description and definition of samples

Samples are taken from references (mean values listed in Tab.1): deep reservoir – ZGL-1 [3, 9, 10] and FGTB-1 [11]; shallow reservoir – BEH-1 [2] and FBe-1 [10]; infiltration zone approximated to Demänová (B-2, LM-45) and Kľačianka springs [5, 12] and combined zone Vyšné Sliače – VŠH-1 and springs [2, 5, 13]. Because of vigorous mixing between some facies, samples of groups that undergo TCM or TTM contact are corrected by a chloride function [14].

III. SILICA GEOTHERMOMETRY

A. Silica solubility and stability

Silica geothermometers reflect to temperature-controlled solubility of quartz and its polymorphs (chalcedony, cristobalite, amorphous silica), assuming equilibrium at the rock-water-solute contact [15]. The quartz is the most stable and least soluble solid silica form in conditions of 120 (mature systems) or 180 (mature, immature systems) – 330 °C [16], controlling SiO2 concentration within the range. Ambiguity appears at 120 - 180 °C interval, as chalcedony becomes metastable and more soluble. Thereafter, below 120 °C it is possible that chalcedony controls the SiO2 content preferentially.

TABLE I. TABLE I. MEAN REPRESENTATIVE CHEMICAL DATA.

Param

etera

Representative samples

ZGL-1 b

ZGL-1 c

FBe-1 b

B-2 b

LM-45 d

VŠH-1 b

Mg 160 269 167 208 185 152

SiO2 51 60 27,2 30 23,5 29

T.D.S 2885 3559 3574 3681 3768 3076

pH 6,5 6,2 6,6 6,4 6,5 6,4

a. concentrations / salinity – T.D.S. in (mg/l), alkalinity (-)

b. wellhead samples

c. deep borehole samples

d. natural discharge springs samples

Other silica forms are rather rare, potentially governing SiO2 concentration in a fluid at temperature below 60 °C [17, 18].

B. Dynamic controls on silica solubility

Erroneous conclusions are usually avoided once several conditions are considered in saturated zone or fluids: sufficient silica source in host rocks [19]; pore-fluid pressure is fixed by a vapor pressure of pure water in case of double-phase existence; any thermal – cold water contact during fluid vertical ascends; neither conductive cooling, nor adiabatic cooling (boiling) controls intrareservoir fluid regime [20]. Abundance of aqueous silica is a function of rock mineralogy and water-rock or water-water ion exchange at a contact with thermal fluid [21], whereby hydrolytic dissociation is the most efficient [15].

Minerals of a quartz group, K-Mg phyllosilicates (e.g. illite, micas, chlorite) or tectosilicates (albite, adularia, feldspars, zeolites) are most frequent in siliciclastics or acid to intermediate magmatic rocks. Carbonates are generally low in silica content, providing less reliable source [22]. While a lack of source forces undersaturation and temperature underestimation, at excess source a resultant temperature assessment is determined at intensity of dissolution [21]. Fixation of pore fluid pressure at a pure-water vapor pressure controls boiling-induced increase in pH resultant to loss in CO2, increasing silica solubility [23], so that reservoir temperature may be overestimated. Mixing of two fluids at different temperatures (thermal – thermal or cold – thermal) brings decrease in SiO2 content of the thermal end-member, thus calculated temperatures appear low [24]. Reversal process is, however, not necessary for cold-water component. Similarity in temperature underestimation is observed for conductive cooling, as fluid ascends or leaks from reservoir environment. At high velocities (fissured, karst-fissured permeability) a fluid is not able to re-equilibrate with SiO2 consequent to loss in temperature, as silicates precipitate [25]. At the same time, intragranular permeability is typical for slow filtration velocities enabling re-equilibration, reducing SiO2 precipitation, thus apparent temperatures are over the anticipated level [26]. Adiabatic boiling then, due to enormous loss in pressure and volatization of saturated vapor, causes decrease in residual liquid volume over an increase in SiO2 content so calculated temperature turns overestimated [25, 27].

C. Silica geothermometers

Majority of geothermometers are designed on principles of non-boiling conditions before sampling. Still, reservoir

Figure 2. Bešeňová elevation – conceptual scheme.

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Figure 3 SiO2 vs reciprocal T (a) and Mg (b) equilibrium functions.

thermodynamics defined a need to specify functions corrected for adiabatic cooling in case of a steam loss [17], especially for quartz and chalcedony, both able to govern reliable results over 60 °C [28]. Conductive geothermometers for quartz (1) [28] or listed in [29, 30], apply to solely cooling springs at sub-boiling temperatures and deep well samples

T (°C) = [1309 / (5,19 – log cSiO2)]-273,15. (1)

Quartz correction for boiling (2) compensates loss of steam

and increase in residual SiO2 simultaneous to adiabatic fluid expansion related cooling due to decrease in the hydrostatic – hydrodynamic pressure head. Modified geothermometer is best to apply on boiling springs of high (> 2 kg.s

-1) discharges and

reservoir samples under active boiling [28].

T (°C) = [1315 / (5,205 – log cSiO2)]-273,15. (2)

Chalcedony geothermometers are used in case it controls

SiO2 concentration or if quartz geothermometers indicate high (> 100 °C) temperatures for low enthalpy fields. Carbonates rich in CO2 sometimes favors boiling (3) [29]

T (°C) = [1264 / (5,31 – log cSiO2)]-273,15. (3)

Low enthalpy reservoirs, however, usually do not provide

conditions for adiabatic cooling, neither discharging springs are at sub-boiling conditions [31], thus conductive chalcedony geothermometers (4) [28] or 28, 29, 30] appear valid

T (°C) = [1032 / (4,69 – log cSiO2)]-273,15 (4)

If calculated temperatures are high, it is be possible that less

abundant amorphous silica (5) or cristobalite alpha (6) and beta (7) control SiO2 aqueous content [28]

T (°C) = [731 / (4,52 – log cSiO2)]-273,15 (5)

T (°C) = [1000 / (4,78 – log cSiO2)]-273,15 (6)

T (°C) = [781 / (4,51 – log cSiO2)]-273,15. (7)

All concentrations (c) are substituted in (mg/l).

D. Silica geothermometers

As discussed in [22], enthalpy balance predefines its conservation at a thermal - cold fluid contact and in a case of iso-enthalpic boiling (there is no temperature conservation in solid). A plot of enthalpy versus silica indicates an initial enthalpy or SiO2 content of end-member and reveals mixing prior sampling, if linear trend is recorded. If a trend is extrapolated to a steam-loss line, boiling may be implied [19].

IV. GEOTHERMOMETRY APPLICATION

A. Controls on silica concentration

There is a temperature associated SiO2 oscillation close to chalcedony equilibrium line (Fig. 3a) up to a region of quartz oversaturation or α-cristobalite undersaturation (local extremes,) implying combined control of various silica forms on dissolved SiO2 concentration. According to mixing conception [2, 5, 7, 8] and majority of population grouping, a lack or excess in SiO2 results from mixing and filtration velocities. Indeed, reservoir dynamics turn chalcedony unstable, defining its control on SiO2 concentration.

B. Implications of reservoir processes

Reciprocal relation in aqueous SiO2, Mg and K content (Fig. 3b) is typical for saturated environment where carbonates prevail over siliciclastics [14, 21], as temperature and residency control resultant dolomite and silicates solutes [25]. In deep reservoir, equilibrium temperature discrepancy (compared to Fig. 5) is consequent to variation in K

2/Mg ratio with

increasing temperature, implying deep dolomite dissolution and uptake of K in clays, simultaneous to weak SiO2 discompaction from detritic additives in carbonates. Oversaturation to chalcedony reflects base overheating forced convection in reservoir [6], as high vertical ascending velocity is greater than capacity of SiO2 to re-equilibrate. Two facies are distinguished in shallow reservoir.

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A population close to 60 °C is affine to fluids of deep reservoir, however, records lack in SiO2 and increase in K

2/Mg

(Fig. 3b). Explanation may be found in mixing (Fig. 4), evidenced by precipitation of chalcedony and Mg-minerals (dolomite, illite) as ascending fluids cool conductively prior they invade shallow zone and mix with autochthonous waters. Thereafter, temperature infers value of last re-equilibration at a top of deep zone, after that ascending velocity is faster than ability of chalcedony and K

2/Mg geothermometer to re-

calibrate. A second population expresses transition between 40 °C – 60 °C increasing K

2/Mg ratio compared to relatively

stable SiO2 level, accepted as an effect of “low” temperature driven intraformation convection over that fluids leach K from feldspars and K-silicates at a contact with Jurassic – Mid Cretaceous pelite carbonates at a base of Choč Nappe dolomites and mix with invaded fluids. Temperature differences are not high enough to force secondary waters to precipitate silica, thus 40 °C correspond to basal mixing temperature, while a level of 60 °C is relic from deep reservoir invasions. Samples of the Sliače discharge zone cluster and express similarity to deep and shallow reservoir (Fig. 3b). Extrapolation of local trend gives equilibrium temperature of 60 °C consistent to a level at a top of deep reservoir. Lack of silica is consequent to chalcedony precipitation after deep reservoir fluids laterally leak and cool conductively. Decrease in K

2/Mg is due to K+ uptake in clays faster than its dissolution

from Paleogene and Jurassic – Cretaceous formations (effect of lateral evasion from shallow reservoir) or Mg

2+ deposition in

dolomites due to cooling of laterally filtrating fluids from deep reservoir. Similarly, magnitude of Mg

2+ and SiO2 deposition in

Mg-silicates is lower than Magnesium intake from fresh infiltrations.

C. Evidence on mixing

Silica and K2/Mg ratio variation evidenced mixing is

examined at silica-enthalpy mixing model. Deep reservoir shows enthalpy of 558 kJ/kg or temperature of 84 °C, decently expected at a base, with close correlation to values attained by geothermometers. Extending trends of shallow reservoir and discharge zone through a region of deep reservoir up to a line of equilibrated chalcedony solubility gives endmember temperature of 69 °C or 64 °C (Fig. 4) respectively, to evidence a common source for both facies, thus mixing.

Figure 4 Silica – enthalpy mixing model.

D. Geothermometry correlation

Both chalcedony geothermometers (boiling -B, non-boiling - NB) are adequate for deep reservoir (Fig. 5), obtaining intraformation temperature of the whole profile (Tmed = 74 °C). However, no evidence on boiling excludes acceptance of boiling-corrected model. Other tests reveal clear underestimation (amorphous silica, cristobalites) or overestimation (quartz). Use of silica geothermometry in shallow reservoir, infiltration or discharge zone is ambiguous. Instability in chemical equilibrium to SiO2, mixing and spatial filtration of fluids at different velocities results in cation solutes geothermometry application recommendation.

V. UPDATE ON HYDROGEOCHEMICAL MODEL

Variations in SiO2, K and Mg content, enthalpy-silica relations and thermodynamic equilibrium evaluation when using silica geoindicators provides reliable basis for geochemical model [2, 6 - 9] update regarding occurrence of mixing, boiling, rock dissolution processes and spatial filtration of waters.

Analogously to Demänová – Liptovská Mara geochemical filtration model, mixing between channels of fast (shallow) and slow (deep) transition within infiltration zone is expected prior to conjoint descend towards shallow and deep reservoir (Fig. 6b). Relative TCM contact of dilutive character brings Mg

2+

intake (increase in Mg is typical for any dilution) from shallow channel at a same magnitude as K+ uptake from clays and weathering weakened K-feldspars in Paleogene clastics and Jurassic – Cretaceous pelitic limestones.

Figure 5 Geothermometry correlation.

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Rigure 6 Bešeňová elevation – geochemical conception model update.

In contrast to relatively stable K2/Mg ratio the SiO2 (Fig. 3b)

content records high variability. Undersaturation to

chalcedony is, in fact, due to high ( > 50 %) dilution rate [32]. It is possible that TCM contact of fluids in deep transition

with thermal waters resident in the deep reservoir is of no distinct effect on K – Mg – SiO2 content. Base overheating intensifies vertical convection (Fig. 6d). Fluids respond to movement with increase in K

2/Mg ratio and SiO2 solute due to

prevailing hydrolysis of K- over Mg- silicates during downwell. Silicates are of clay-additives origin from dolomites, approaching (but not reaching) equilibrium at water-rock contact. Upwelling, brings dissolution of Mg from dolomites towards top of a zone faster than dissolution of silicates due to loss in temperature. Observed drop in SiO2 concentration is consequent to low silica deposition as fluids slowly cool conductively.

Shallow reservoir samples record mixing of three microfacies (Fig. 6e). Invasion of deep reservoir fluids that escape deep convection, cool continuously and equilibrate with chalcedony realizes in TTM regime (Fig. 4). Compared to primary fluids, samples express increase in K

2/Mg ratio

inferring Mg2+

minerals precipitation (dolomite, illite), evidenced by lack of solute SiO2. High temperatures calculated by chalcedony geoindicator point on re-equilibration of evading fluids with silica atop of deep reservoir. For facies with equilibrium temperature of 40 – 60 °C (Fig. 3b), increase in K

2/Mg ratio and drop in SiO2 imply the TCM contact of

shallow reservoir fluids with shallow transition infiltrations. With K

2/Mg change interpreted as preferential K

+ leaching

from clay minerals and

K-phyllosilicates within dolomites and Jurassic-Mid Cretaceous pelitic limestones, the mixing realizes at a base of the Choč Nappe dolomite complex. Loss in SiO2 is resultant to Mg-silicates deposition of higher rate than precipitation of dolomites. Mixing of TTM and TCM originated fluids close to the base forces weak convection, over that cooling and initial onset of CO2 evasion turns onset of dolomite precipitation, increasing the K

2/Mg ratio.

Relation between different fluids (Fig. 4) reveals mutual source of waters within discharge zone in facies from deep and shallow reservoir. Simultaneous decrease in K

2/Mg ratio and

SiO2 implies muscovite and adularia deposition control on aqueous SiO2 during cooling. Equilibrium temperature of ≈ 60 °C infers impact of deep fluids on hydrochemistry and TTM mixing between. Lateral leaking and vertical ascending velocity of waters from deep reservoir is faster than capacity of chalcedony geothermometer to attain equilibrium. Precipitation of K-silicates is balanced with K

+ leaching from clays during

shallow reservoir fluids transit in Paleogene formations at a top of Jurassic – Mid Cretaceous pelitic carbonates horizon rich in alkali minerals. Still, both facies deposit dolomite along. To compensate the Mg

2+ loss, usually more intense compared to

drop in K+, another Mg source is necessary. Thereafter, TTM

originated fluids should have to come into contact with infiltrating cold (low mineralized) waters and mix in TCM regime close to the surface, prior they are naturally disposed in form of springs. This is in correlation to regional piezometry [3, 4] as recharges are of very short residency and never enter any transition into reservoirs.

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VI. CONCLUSIONS

Application and interpretation of silica geothermometry provides tool to study reciprocal SiO2-K-Mg relations in terms of formation temperature assessment and definition of unrevealed processes. While at the Bešeňová elevation, the chalcedony controls aqueous SiO2 content, concentration of K

+

and Mg2+

refers to water-rock equilibrium with dolomite, illite, chlorite, chalcedony or adularia. Thermal waters associated with the structure are immature in essence, consequent to various filtration velocities and several mixing contacts. Use of chalcedony geothermometry provides reliable results for deep reservoir only, inferring (Tmed = 75 °C). Basal temperature determined from silica-enthalpy model reaches T = 84 °C, affine to thermal models. At the same time, mismatch in estimated temperatures for other zones interpretation revealed convection within both reservoirs, relative velocities of vertically evading or laterally leaking fluids towards discharge zone faster than capacity of silica and K

2/Mg geothermometer

to recalibrate, and combined, TTM and TCM contact of fluids in the discharge zone. Within, thermal waters from deep and shallow reservoir mix in TTM regime prior a contact with short-residency infiltrations and upwell as springs. Presented model is in concordance to a model of cation solute geothermometry [32], boiling-mixing models [7, 8] and piezometry [3, 4]. As a part of complex hydrogeochemical conception, the study contributes on overall understanding of the Bešeňová elevation hydrogeothermal system in terms of hydrogeochemistry formation, temperature conditions and fluid flow interpretation.

REFERENCES

[1] A. Remšík, M. Fendek, M. Král, D. Bodiš, J. Michalko, Geotermálna energia Liptovskej kotliny [manuscript], ŠGÚDŠ, Bratislava, 97 pp., 1993

[2] O. Franko, D. Bodiš, S. Gazda, M. Michalíček, Hydrogeologické vyhodnotenie Liptovskej kotliny z hľadiska výskytu minerálnych vôd [manuscript], ŠGÚDŠ, Bratislava, 79 pp., 1979

[3] M. Fendek, D. Bodiš, A. Biely, A. Kullmanová, V. Gašparíková, P. Snopková, M. Král, J. Jančí, Správa o výskumnom geotermálnom vrte ZGL-1 v Bešeňovej – overenie prognóznych zdrojov geotermálnej energie Liptovskej kotliny – západ [manuscript], ŠGÚDŠ, Bratislava, 85 pp., 1988

[4] M. Fendek, A. Remšík, “Hodnotenie množstva geotermálnej vody a geotermálnej energie Liptovskej kotliny,” Mineralia Slovaca, 2005, Vol. 37, No. 1-2, pp. 131-136

[5] O. Franko, A. Biely, J. Hricko, V. Szalaiová, L. Mateovič, Zhodnotenie oblasti Demänovej v Liptovskej kotline pre vyhľadávanie termálnych vôd [manuscript], ŠGÚDŠ, Bratislava, 50 pp., 1974

[6] B. Fričovský, L. Vizi, L. Tometz, “Komplexný koncepčný model hydrogeotermálnej štruktúry bešeňovská elevácia (syntéza a reinterpretácia intraštruktúrnych a extraštruktúrnych vzťahov),” Prednáškové popoludnie SAG – SAIG: Východné Slovensko – geologická stavba a geofaktory životného prostredia, 2012, ŠGÚDŠ, Košice, 8th November, unpublished

[7] B. Fričovský, L. Vizi, L. Tometz, “Hydrogeochemistry implications for fluid-flow-tracking based conceptual model: case study on the Bešeňová elevation hydrogeothermal structure (Northern Slovakia),” Proceedings 3rd International Masaryk Conference for Ph.D. students and young researchers, 2012, Hradec Králové, Czech Republic, 10th – 14th December, pp. 3721-3732

[8] B. Fričovský, L. Tometz, “Reservoir boiling and mixing hydrogeochemical models overview and application: case study on the Bešeňová elevation hydrogeothermal structure (Northern Slovakia),” Proceedings Hydrogeochemia ’13 – Aktualne problemy

hydrogeochemii, 14 Miedzynarodowa konferencja naukowa, 2013, Sosnowiec, Poland, 20th – 21st June, pp. 19-21

[9] A. Remšík, M. Fendek, J. Mello, M. Král, D. Bodiš, J. Michalko, D. Maďar, K. Vika, Liptovská kotlina – regionálne hydrogeotermálne zhodnotenie [manuscript], ŠGÚDŠ, Bratislava, 94 pp., 1998

[10] G. Vandrová, P. Štefanka, M. Červeňan, Bešeňová – revízia exploatačných podmienok zdroja ZGL-1 a FBe-1 [manuscript], ŠGÚDŠ, Bratislava, 101 pp., 2009

[11] G. Vandrová, P. Štefanka, J. Hók, M. Sýkora, Bešeňová – hydrogeotermálny vrt FGTB-1 – 1. a 2. etapa [manuscript], ŠGÚDŠ, Bratislava, 140 pp., 2010

[12] M. Klago, B. Stuchlíková, Liptovský Ján – Pod Bielym – hydrogeologický prieskum [manuscript], ŠGÚDŚ, Bratislava, 40 pp., 1990

[13] Ľ. Zbořil, J. Májovský, H. Takáčová, Ľ. Husák, Liptovská kotlina – geoelektrické, plynometrické a termometrícké merania [manuscript], ŠGÚDŠ, Bratislava, 40 pp., 1972

[14] L. Marini, G. Chiodini, R. Cioni, “New geothermometers for carbonate-evaporite geothermal reservoirs,” Geothermics, 1986, Vol. 15, , pp. 77-86

[15] W. F. Giggenbach, “Geothermal solute equilibria” Geochimica Cosmochimica Acta, 1988, Vol. 52, pp. 2749-2765

[16] R. O. Fournier, J.J. Rowe, “Estimation of underground temperatures from the silica contents of water from hot springs and wet steam wells,” American Journal of Science, 1966, Vol. 264, pp. 685-697

[17] R. O. Fournier, “Silica in thermal waters. Laboratory and field investigations,” Proceedings of the International Symposium on Hydrogeochemistry and Biochemistry, 1970, September 7-9 Tokyo, Japan, Vol. 1, pp. 122-139

[18] R. O. Fournier, Application of Water Geochemistry to Geothermal and Reservoir Engineering, Institute of Geology and Mineralogy, Madrid, Spain, pp. 5-56, July 1980

[19] R. O. Fournier, Solubility of silica in hydrothermal solutions: practical applications, United Nations Geothermal Training Programme, Reykjavik, Iceland, Report No. 10, pp. 21-39, 1989

[20] J. D. Rimstidt, H. L. Barnes, “The kinetics of silica-water reactions,” Geochimica Cosmochimica Acta, 1980, Vol. 44, pp. 1683-1699

[21] W. F. Giggenbach, “Mass transfer in hydrothermal alteration systems – A conceptual approach,” Geochimica Cosmochimica Acta, 1984, Vol. 48, pp. 2693-2711

[22] R. O. Fournier, A.H. Truesdell, “Geochemical indicators of subsurface temperature – Part 2,” Journal of Research of U.S. Geological Survey, 1974, Vol. 2, pp. 263-270

[23] A. H. Truesdell, R. O. Fournier, “Procedure for estimating the temperature of a hot water component in a mixed water using a plot of dissolved silica versus enthalpy,” Journal of Research of U.S. Geological Survey, 1977, Vol. 5, No. 1, pp. 49-52

[24] S. Arnorsson, A. Stefansson, J. Bjarnasson, “Fluid-fluid interactions in geothermal systems,” Reviews in Mineralogy and Geochemistry, 2007, Vol. 66, No. 2, pp. 259-312

[25] M. Guidi, L. Marini, G. Scandiffio, R. Cioni, “Chemical geothermometry in hydrothermal aqueous solutions: the influence of ion complexing,” Geothermics, 1990, Vol. 19, No. 2, pp. 415-441

[26] F. Tonani, “Some remarks on the application of geochemical techniques in geothermal exploration,” Proceedings 2nd Symposium on Advances in European Geothermal Resources, 1980, Strasbourg, France, pp. 428-443

[27] M. H. Reed, N. F. Spycher, “Calculation of pH and mineral equilibria in hydrothermal waters with application to geothermometry and studies of boiling and dilution,” Geochimica Cosmochimica Acta, 1984, Vol. 48, pp. 1479-1492

[28] R. O. Fournier, “Chemical geothermometers and mixing models for geothermal systems,” Geothermics, 1977, Vol. 5, pp. 31-40

[29] S. Arnorsson, E. Gunnlaugsson, H. Svavarsson, “The chemistry of geothermal waters in Iceland – II: Mineral equilibria and independent variables controlling water composition,” Geochimica Cosmochimica Acta, 1983, Vol. 47, pp. 547-566

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[30] A. H. Truesdell, R. O. Fournier, “Calculation of deep temperatures in geothermal systems from the chemistry of boiling spring waters of mixed origion,” Proceedings 2nd UN Symposium on Geothermal Resources, 1975, San Francisco, CA, USA, pp. 53-63

[31] S. Arnorsson, F. D’Amore, J. Gerardo, Isotopic and chemical techniques in geothermal exploration, Vienna, Austria, 2000, 351 p.

[32] B. Fričovský, L. Tometz, “Cation solute geothermometry interpretation and application in low enthalpy geothermal systems: Case study on the Bešeňová elevation structure, Liptov Basin, Northern Slovakia,” not published

SECTIONNatural science - physics

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RSA

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Scientific

Areas-VIRTUA

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CONFERENCE-

The 2nd year of Advanced Research in Scientific Areashttp://www.arsa-conf.com

Advanced Research in Scientific Areas

December, 2. - 6. 2013

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